Unintended activity in homologous muscle during intended unilateral contractions increases with greater task difficulty.
Unintended activity in homologous muscle during intended unilateral contractions increases with greater task difficulty.
复制标题
在有意的单侧收缩期间，同源肌肉的意外活动随着任务难度的增加而增加。
DOI：
10.1007/s00421-017-3689-7
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Yoshitake Y.
中科院分区：
文献类型：
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作者：
Watanabe H;Kanehisa H;Yoshitake Y.
目的研究任务难度对健侧同侧肌肉非预期肌肉激活（UIMA）水平的影响，以及不同任务难度对UIMA水平的影响，和（3）在单侧有意力匹配任务中，有意和对侧低频无意肌肉活动之间的时间相关性。（21.8 ± 2.4岁）和12名（69.9 ± 5.3岁）成年男性，以最大随意收缩力的20-80%进行稳定的左手食指等长外展。通过调整以显示器上用于视觉反馈的目标力为中心的两个条之间的间距来设置两个任务难度。计算双手的表面肌电图（aEMG）的振幅，并相对于最大值进行归一化。为了确定是否预期和非预期的肌肉活动之间的振荡是相关的，交叉相关函数（CCF）的整流肌电图双手在低频率计算样本被认为是adequate.ResultsThe非预期的aEMG（右手）有显着的主要影响任务难度，年龄，和目标力（所有P < 0.05），没有任何相互作用。不同的显着峰值CCF（平均0.38，P< 0.05）与小的时间滞后之间存在的14的17个samples.ConclusionsThe目前的结果表明，UIMA增加更大的任务难度，无论年龄，和时间的相关性之间存在有意和对侧无意的肌肉活动在低频。
PurposeThe present study aimed to examine (1) the effect of task difficulty on unintended muscle activation (UIMA) levels in contralateral homologous muscle, (2) the difference between young and old adults in degree of UIMA with respect to task difficulty, and (3) temporal correlations between intended and contralateral unintended muscle activity at low frequency during unilateral intended force-matching tasks.MethodsTwelve young (21.8 ± 2.4 years) and twelve old (69.9 ± 5.3 years) adult men performed steady isometric abductions with the left index finger at 20–80% of maximal voluntary contraction force. Two task difficulties were set by adjusting the spacing between two bars centered about the target force used for visual feedback on a monitor. The amplitude of surface electromyogram (aEMG) for both hands was calculated and normalized with respect to the maximal value. To determine if oscillations between intended and unintended muscle activities were correlated, cross-correlation function (CCF) of rectified EMG for both hands at low frequency was calculated for samples deemed adequate.ResultsThe unintended aEMG (right hand) had significant main effects in task difficulty, age, and target force (allP< 0.05) without any interactions. Distinct significant peaks in CCF (0.38 on average,P< 0.05) with small time lags were present between rectified EMGs of intended and unintended muscles in 14 of the 17 samples.ConclusionsThe current results indicate that UIMA increases with greater task difficulty regardless of age, and temporal correlations exist between intended and contralateral unintended muscle activities at low frequency.